U.S. patent number 6,100,316 [Application Number 08/765,919] was granted by the patent office on 2000-08-08 for radiation-curable coating materials and their use for the production of matt coating films.
This patent grant is currently assigned to BASF Coatings AG. Invention is credited to Martin Lobert.
United States Patent |
6,100,316 |
Lobert |
August 8, 2000 |
Radiation-curable coating materials and their use for the
production of matt coating films
Abstract
The invention relates to radiation-curable coating materials
which comprise A a synthetic resin containing from 1.5 to 5 mol/kg,
preferably from 3.6 to 4.5 mol/kg, of ethylenically unsaturated
double bonds of which not more than 10% are vinyl groups, or a
mixture of such synthetic resins, and B a compound of the general
formula Ar--O--R.sub.1 --O--CO--CR.sub.2 .dbd.CH.sub.2, where Ar is
an optionally substituted aryl radical, R.sub.1 is an alkylene
radical having 1 to 6 carbon atoms and R.sub.2 is a hydrogen atom
or an alkyl radical having 1 to 3 carbon atoms, or a mixture of
such compounds, from 10 to 70% by weight of the total quantity of A
and B comprising component A and from 30 to 90% by weight of the
total quantity of A and B comprising component B.
Inventors: |
Lobert; Martin (Osnabruck,
DE) |
Assignee: |
BASF Coatings AG
(Muenster-Hiltrup, DE)
|
Family
ID: |
6522653 |
Appl.
No.: |
08/765,919 |
Filed: |
January 6, 1997 |
PCT
Filed: |
July 04, 1995 |
PCT No.: |
PCT/EP95/02583 |
371
Date: |
January 06, 1997 |
102(e)
Date: |
January 06, 1997 |
PCT
Pub. No.: |
WO96/01858 |
PCT
Pub. Date: |
January 25, 1996 |
Foreign Application Priority Data
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Jul 8, 1994 [DE] |
|
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44 24 101 |
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Current U.S.
Class: |
523/500; 522/104;
522/107; 522/141; 525/303; 526/313 |
Current CPC
Class: |
C09D
4/06 (20130101); C09D 167/06 (20130101); C09D
175/14 (20130101); C09D 4/06 (20130101); C08F
283/00 (20130101); C09D 167/06 (20130101); C09D
175/14 (20130101); C08L 2666/34 (20130101); C08L
2666/34 (20130101) |
Current International
Class: |
C09D
167/06 (20060101); C09D 4/06 (20060101); C09D
175/14 (20060101); C08L 067/00 () |
Field of
Search: |
;522/104,107,141
;523/500,522,523,526 ;525/303 ;526/313 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 311 288 |
|
Apr 1989 |
|
EP |
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WO 90/05061 |
|
May 1990 |
|
WO |
|
Primary Examiner: Michl; Paul R.
Claims
What is claimed is:
1. A process for the production of a matt coating film having a
gloss of between 3 and 50 units according to DIN 67 530,
comprising
applying a radiation-curable coating material to a substrate, the
coating material comprising
A. a synthetic resin containing from 3.6 to 4.5 mol/kg of
ethylenically unsaturated double bonds of which not more than 10%
are vinyl groups, or a mixture of such synthetic resins, and
B. a compound of the general formula Ar--O--R.sub.1
--O--CO--CR.sub.2 .dbd.CH.sub.2, wherein Ar is an optionally
substituted aryl radical, R.sub.1 is an alkylene radical having 1
to 6 carbon atoms, and R.sub.2 is a hydrogen atom or an alkyl
radical having 1 to 3 carbon atoms, or a mixture of such compounds,
and
wherein A comprises from 10 to 70% by weight and B comprises from
30 to 90% by weight of the total quantity of A and B; and
curing the coated substrate by the application of radiation to
produce a coated substrate having a having a gloss of between 3 and
50 units according to DIN 67 530.
2. A process according to claim 1, wherein component A comprises a
polyester resin or a mixture of polyester resins.
3. A process according to claim 1, wherein Ar is a phenyl
radical.
4. A process according to claim 1, wherein R.sub.1 is an alkylene
radical having 1 to 3 carbon atoms.
5. A process according to claim 1, wherein R.sub.2 is a hydrogen
atom or a methyl radical.
6. A process according to claim 1, wherein component B comprises
phenoxyethyl acrylate.
Description
FIELD OF THE INVENTION
The invention relates to radiation-curable coating materials and to
the use of these radiation-curable coating materials for the
production of matt coating films.
BACKGROUND AND SUMMARY OF THE INVENTION
Radiation-curable coating materials are known. They are coating
compositions which are cured using high-energy radiation,
especially using UV radiation or using electron beams. With the
known radiation-curable coating materials it is possible without
problems to prepare coating films which are highly glossy to
silkily glossy (degree of gloss of between 100 and 50 units
according to DIN 67 530 at a measurement angle of 60.degree.).
In contrast, the production of matt coating films gives rise to
great difficulties. There exists a series of proposals for solving
this technical problem. According to DE-A-29 47 597, coating
materials are employed which contain a combination of
radiation-curable and heat-curable binders. Disadvantages when
using such coating materials are that a baking step is necessary
and, when highly reactive heat-curable components are employed, the
coating materials must be stored as multicomponent systems. DE-A-22
44 327 describes a technically very complex process for the
production of matt coating films, in which the radiation-curable
coating material is cured in a first step in an atmosphere which
contains at least 5000 ppm of oxygen and subsequently in a second
step in an atmosphere which contains less than 1000 ppm of oxygen,
by irradiation with high-energy radiation. According to DE-A-41 18
731, matt coating films are prepared by recoating an already coated
area with a radiation-curable coating material which contains
matting agents, the radiation-curable coating material being
applied in a coat thickness such that the cured coating film has a
thickness which is less than the average particle size of the
matting agent. This process too is associated with high technical
effort, since it requires the application of an additional coat,
and requires the thickness of the additionally applied coat to be
accurately controlled.
The object of the present invention was to provide
radiation-curable coating materials with which it is possible,
without great technical effort, to prepare matt coating films.
It has been possible, surprisingly, to achieve this object by the
provision of radiation-curable coating materials which are
characterized in that they contain
A a synthetic resin containing from 1.5 to 5 mol/kg, preferably
from 3.6 to 4.5 mol/kg, of ethylenically unsaturated double bonds
of which not more than 10%, preferably not more than 5%, are vinyl
groups, or a mixture of such synthetic resins, and
B a compound of the general formula Ar--O--R.sub.1
--O--CO--CR.sub.2 .dbd.CH.sub.2, where Ar is an optionally
substituted aryl radical, preferably a phenyl radical, R.sub.1 is
an alkylene radical having 1 to 6 carbon atoms, preferably an
alkylene radical having 1 to 3 carbon atoms, very preferably a
--CH.sub.2 --CH.sub.2 -- radical, and R.sub.2 is a hydrogen atom or
an alkyl radical having 1 to 3 carbon atoms, preferably a hydrogen
atom or a methyl radical, or a mixture of such compounds,
from 10 to 70%, preferably from 20 to 60%, by weight of the total
quantity of A and B comprising component A and from 30 to 90%,
preferably from 40 to 80%, by weight of the total quantity of A and
B comprising component B.
Using the radiation-curable coating materials provided in
accordance with the invention it is possible, surprisingly and
using the application devices and application methods customary for
radiation-curable coating materials, to produce matt coating films,
especially coating films having a degree of gloss of between 3 and
50 units according to DIN 67 530 (measured at a measurement angle
of 60.degree.).
DETAILED DESCRIPTION
The synthetic resins employed as component A in the coating
materials according to the invention are generally known and
commercially available. Component A may, for example, be a
polyester resin, a polyacrylate resin or a polyurethane resin, or a
mixture of such resins. Component A preferably comprises a
polyester resin.
Polyester resins which can be employed as component A may be
prepared in a conventional manner from polyols and polycarboxylic
acids, with the optional use of monools and/or monocarboxylic
acids. The introduction of ethylenically unsaturated double bonds
into the polyester resins can be effected by using polyols
containing ethylenically unsaturated double bonds and/or
polycarboxylic acids containing ethylenically unsaturated double
bonds and/or monools containing ethylenically unsaturated double
bonds and/or monocarboxylic acids containing ethylenically
unsaturated double bonds. As component A it is very particularly
preferred to employ polyester resins which have been prepared from
fumaric or maleic acid,
tetrahydrophthalic acid and diethylene glycol.
As component B, the radiation-curable coating materials according
to the invention very particularly preferably contain phenoxyethyl
acrylate.
In addition to components A and B, the coating materials according
to the invention may also contain from 0.01 to 66%, preferably from
10 to 40%, by weight, based on A+B.dbd.100% by weight, of C matting
agents and/or fillers. As component C the coating materials
according to the invention may contain all matting agents and/or
fillers which can be employed in radiation-curable coating
materials. Examples which are mentioned are silicic acid, barium
sulfate, talc, polyolefin waxes, polyamide waxes and kaolin. As
component C it is preferred to employ highly disperse silicic
acid.
The coating materials according to the invention may also contain
from 0.01 to 33%, preferably 5 to 25%, by weight based on
A+B.dbd.100% by weight, of D pigments. As component D, the coating
materials according to the invention may contain all pigments which
can be employed in radiation-curable coating materials.
In addition to components A, B, C and D the coating materials
according to the invention may also contain further binders, other
than component A, which are suitable for radiation-curable coating
materials, for example vinyl group-containing polyacrylates or
polymethacrylates, polyester acrylates, polyether acrylates or
epoxy acrylates, and low molecular weight aliphatic or
cycloaliphatic esters of acrylic or methacrylic acid, and other
additives which are customary for radiation-curable coating
materials, for example photoinitiators, adhesion promoters,
deaerating agents, wetting auxiliaries, anti-settling agents, and
leveling auxiliaries.
The coating materials according to the invention can be cured with
the aid of high-energy radiation. They are preferably cured with
the aid of UV radiation or with the aid of electron beams. If
curing is to be effected by means of UV radiation, at least one
photoinitiator suitable for UV-curable coating materials is
advantageously added to the coating materials.
The radiation-curable coating materials according to the invention
can be applied with the aid of all application methods which are
suitable for radiation-curable coating materials to any desired
substrates, for example metal, glass, wood, wood materials, for
example fiberboard or MDF (medium density fiber) boards, plastic
and paper, and then cured by means of high-energy radiation. In
this way it is possible, surprisingly, to produce matt coating
films with low degrees of gloss (down to 3 units according to DIN
67 530 at a 60.degree. measurement angle). The coating films
produced with the coating materials according to the invention are
distinguished by high mechanical and chemical resistance.
The invention is illustrated in more detail in the embodiment
examples. All indications of parts and percentages are to be
understood as indications by weight, unless expressly stated
otherwise.
2.0 parts of a mixture comprising 23.1 parts of an unsaturated
polyester resin (constituents: 24.9% by weight fumaric acid, 6.2%
by weight maleic acid, 44.5% by weight diethylene glycol and 24.3%
by weight tetrahydrophthalic acid) and 18.9 parts of dipropylene
glycol diacrylate
0.3 parts of a commercial dispersion auxiliary,
7.0 parts of highly disperse silicic acid,
21.0 parts of talc,
14.0 parts of rutile pigment (RHD-2, manufacturer: Tioxide),
and
3.5 parts of phenoxyethyl acrylate
are weighed into a mixer and dispersed for 20 minutes at 3000 rpm
with a dissolver. Subsequently, 12.2 parts of phenoxyethyl acrylate
are used to establish a viscosity of 45 s according to DIN 53211-4
at a temperature of 20 degrees Celsius.
The coating material described above is applied (75 g/m.sup.2) to a
primed and sanded (cross-sander with 220 grain) fiberboard using a
curtain coating machine, and is cured with electron beams
(acceleration voltage 180 kV; dose 120 kGy). The degree of gloss of
the coat thus obtained is 3 units (according to DIN 67530,
measurement angle 60.degree.).
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